The European Space Observatory (ESO) has released an impressive 9-gigapixel image of the central part of the Milky Way Galaxy. The historic image contains some 84 million stars and represents the largest ever catalog of the center of our home galaxy.
The image was taken by the Visible and Infrared Survey Telescope for Astronomy (VISTA) at the ESO Paranal Observatory in Chile, using three different infrared filters to cut through dust fields that would usually obscure the view. Measuring a spectacular 108,500 x 81,500 pixels, it contains more than ten times the number of stars found in any previous study. If the image were to be printed at the resolution of a typical book, it would measure a full 9 x 7 meters (29.5 x 23 feet). Despite the impressive detail and staggering scale of the work, it actually only covers some 315 square degrees of the sky – less than one percent of the entire sky.
In addition to being a visual marvel, the image also serves a practical purpose. By plotting the brightness and color of the stars, astronomers are able to build a more complete understanding of both our home galaxy, and spiral galaxies in general. The data is used to create a color-magnitude diagram, a valuable tool in measuring physical properties of stars, such as their temperatures, masses and ages.
The VISTA telescope has produced a number of spectacular images in the past. In April 2010 it released an infrared view of the Cat's Paw Nebula, one of the most active stellar nurseries in our galaxy, with some stars measuring nearly ten times the mass of our sun.
A similar (and no less spectacular) image of the Orion Nebula was released in February 2010. However, unlike the impressive 315 square degrees covered by the telescope's latest offering, the images of the Orion and Cat's Paw Nebulas represent just 1.5 x 1 and 1 x 1 degrees of sky respectively.
The Milky Way image was taken as part of a public survey project, meaning that all of the data is readily available through the ESO data archive. However, you might want to check the speed of your internet connection before downloading the original 24.6 GB image.
Click the source link below to check out the incredible image in all of its 9-gigapixel, zoomable glory.